OT Security Engineer Location: Dublin, Ireland Employment Type: Full-Time Salary: €75,000 - €90,000 A technical team expanding its operational technology footprint is adding a Security Engineer who thrives inside the guts of OT networks and production systems-not just observing from the perimeter. The work is heavily engineering-focused, with hands-on design, implementation, and troubleshooting across controllers, machinery, and security controls. This is a role for someone who wants to influence how the environment matures while delivering practical security outcomes. The Role Build, tune, and validate security controls across OT networks and production platforms. Design and refine segmentation boundaries, zoning layouts, and routing patterns. Engineer and maintain firewall rule sets, ACL structures, and traffic pathways between operational layers. Lead equipment onboarding-interface mapping, communication validation, and control-plane behaviour checks. Build and maintain baseline configurations for switches, controllers, edge devices, and monitoring points. Analyse system behaviour, cross-talk, and unexpected signalling patterns during change windows. Implement and validate security controls with minimal performance impact on production systems. Perform engineering-focused incident triage: packet inspection, log correlation, device state review, rollback reasoning. Contribute to internal architecture reviews and maintain technical design notes, diagrams, and configuration references. Work with external partners to align environments, validate remediation plans, and verify technical changes. Strengthen observability-logging routes, telemetry capture, and health-state indicators for OT assets. Skills & Experience 5+ years in OT network engineering, ICS/SCADA systems, or industrial networking environments. Strong understanding of segmentation, VLAN layouts, protocol behaviour, and controller communication paths. Experience configuring and maintaining firewalls and L2/L3 network equipment in production. Familiarity with frameworks such as NIST 800-82 or IEC 62443 applied in operational engineering scenarios. Ability to interpret traffic flows, protocol anomalies, and equipment state transitions. Hands-on experience with packet analysers, vulnerability scanners, endpoint controls, and configuration management tools. Comfortable operating in controlled, regulated, or compliance-bound industrial environments. Clear, structured documentation habits-baseline diagrams, change notes, configuration references. Experience performing technical root-cause investigations and contributing to OT security improvement plans. Reperio Human Capital acts as an Employment Agency and an Employment Business. Skills: OT Networks Dublin Security Firewalls Monitoring Compliance Benefits: Work From Home